Abrading machine



y 12, 0 P. ERNST 3,510,987

ABRADING MACHINE Filed March 21, 1968 3 sh t 1 INVENTOR PAUL ERNST AGENT May-12,1970

' P. ERNST ABRADING MACHINE 3 Sheets-Sheet 2 Filed March 21, 1968 I IVL-A wwN AMI Ulllllll nu I"..-

I N VENTOR PAUL ERN T Km QM,

AGENT May 12, 1970 P. ERNST 3,510,987

ABRADING MACHINE Filed March 21, 1968 3 Sheets-Sheet 5 F|G.4 O

2O 3 l3 I4 I "III Ill'l IIIIII I'IIIIIII "I G 4 m n j n G II N r II II II II 3 I J 28 28 L T j I 1 INVENTOR 27 2 9 7 25 PAUL ERNST AGENT United States Patent O 3,510,987 ABRADING MACHINE Paul Ernst, Kandelstrasse 16, Eschelbronn, Germany Filed Mar. 21, 1968, Ser. No. 714,952 Claims priority, applicatig; 6( gtgrmany, Mar. 22, 1967,

9 Int. Cl. 1824b 21/08 US. Cl. 51138 7 Claims ABSTRACT OF THE DISCLOSURE In an abrading machine wherein the abrading band is pressed against a work piece by a pressure beam, a carrier frame for the pressure beam including a pair of pivots mounted on the lateral ends of the frame for pivoting about an axis extending in the direction of movement of the endless abrading band, and upright, horizontal and oblique lever arms affixed to each pivot for pivoting in unison therewith, the oblique lever arm enclosing an acute angle with the conveyor which moves the work piece in the direction of its length into contact with the endless abrading band which moves in a direction transverse thereto.

BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates to an apparatus for abrading the surface of a work piece, and may be useful for abrading or polishing plates or like parts having flat surfaces of such materials as steel or other metal, rigid synthetic resins, plywood, and the like.

It is a primary object of this invention to provide an abrading machine of relatively simple construction, which is adaptable to work pieces of various widths, which assures troublefree contact between the abrading band and the work piece surface, and in which undesirable rounding of the work piece edges is avoided.

The apparatus of the invention comprises a conveyor for moving the work piece in the direction of its length to an abrading station, an endless band of abrasive material mounted for movement in contact with, and in the direction of the width of, the work piece surface at the abrading station, and a pressure means arranged to press the endless band of abrasive material against the surface over its entire width at the abrading station.

The above and other objects are accomplished by the provision of a carrier frame for the pressure means extending in the direction of the length of the work piece and having a width exceeding the width of the endless band whereby the two lateral ends of the carrier frame project beyond the width of the endless band. The carrier frame includes a pivoting element mounted on each lateral end of the carrier frame for pivoting about an axis extending in the direction of the movement of the endless band. An upright lever arm means is afiixed to each pivoting element for pivoting in unison therewith, a horizontal lever arm means is affixed to each pivoting element for pivoting in unison therewith, and an oblique lever arm means is aflixed to each pivoting element for pivoting in unison therewith, the oblique lever arm means enclosing an acute angle with the conveyor in the direction of its movement. In the illustrated embodiment, each lever arm means consists of a series of like levers adjacently mounted on the pivoting elements along the axes thereof. Sensing rollers are at the outer ends of the oblique lever arms.

The combination of the pivotal levers on the carrier frame for the pressure means has the result that pressure is exerted upon the work piece surface only at those points where the Sensing rollers are lifted up. No pres- 3,510,987 Patented May 12, 1970 sure is exerted along the longitudinal edges of the work piece so that these edges are not rounded by abrasion.

In accordance with one feature of this invention, a series of pressure rollers transmit the pressure from the pressure means to the endless abrading band, thus providing rolling frictional engagement therebetween.

According to another feature of the invention, uniform distribution of the pressure also over the gaps between the series of pressure rollers is assured by mounting a steel band between the pressure rollers and the abrading band. In this manner, substantially the entire energy is used for a'brading or polishing.

BRIEF DESCRIPTION OF THE DRAWING The above and other objects, features and advantages of the present invention will become more apparent in the following detailed description of two preferred embodiments, taken in conjunction with the accompanying drawing wherein:

FIG. 1 is a schematic side view of the one embodiment of an abrading machine according to this invention;

FIG. 2 is a similar view of another embodiment thereof;

FIG. 3 is a section along line III-III of FIG. 1, with certain elements removed for claritys sake; and

FIG. 4 is an end view of the machine of FIG. 1, seen in the direction of arrow 6, the view of FIGS. 3 and 4 being schematic.

Referring now to the drawing and first to FIGS. 1, 3, and 4, the machine is shown to include an endless conveyor 27 moving the work piece 7 in the direction of arrow 6, i.e. in the direction of the length of the work piece to the illustrated abrading station. Rotata-ble rolls 24, 25 support the conveyor band and the work piece at the abrading station underneath the endless band 21 of abrading material. As best seen in FIGS. 3 and 4, the endless abrading band is mounted for movement in contact with, and in the direction of the width of, the surface of Work piece 7 at the abrading station.

The abrading band may be a suitable abrasive paper or emery cloth. An endless steel pressure band 20 is trained over pulleys 28, 28, one of the pulleys being rotated by a power source (not shown) to move the pressure band continuously. A felt cloth or like friction-producing means is interleaved between the steel band 20 and the abrading band 21 whereby the abrading band is continuously moved along with the steel band, the abrading band being trained over guide roller 29.

The endless abrasive band is pressed against the surface of the work piece at the abrading station in the following manner:

A carrier frame 1 extends in the direction of the length of the work piece and has a width exceeding the Width of the endless band 21 whereby the two lateral ends of the carrier frame project beyond the width of the endless abrading band. Two pivoting elements 2, 2' are mounted on each lateral end of the carrier frame by pivot bolts 3, 3' for pivoting about an axis extending in the direction of the movement of the endless band. The illustrated pivoting elements are cross beams extending transversely of the direction of movement of the work piece.

Upright lever arm means 4, 4', horizontal lever arm means 5, 5 and oblique lever arm means 8, 8" are aflixed to each pivoting element for pivoting in unison therewith, the illustrated lever arm means consisting of a series of like levers adjacently mounted on the pivoting elementstive ones of the outer ends of upright levers 4, 4', the connecting rods extending in the direction of the length of the work piece. A like series of U-shaped carriers 11 constitutes a carrier means having a horizontal bar means consisting in the illustrated embodiment of a series of horizontal bars 12 extending in the direction of the length of the work piece. The U-shaped carrier means links the outer ends of the horizontal lever means of each of the pivoting elements. Sensing roller means constituted in the illustrated embodiment by a series of rollers 9, 9' are mounted at the outer ends of the oblique lever arms 8, 8. The connecting rods 1t? interconnect the upright lever arms of the two pivoting elements into a unit so that they will swing in unison when only the arms of one pivoting element are pivoted, thus assuring full contact with the work piece until both series of rollers '9, 9" have left the work piece.

A stop 14 is mounted on carrier frame 1 and the tension spring 13, whose ends are connected to the stop bar and to horizontal lever arm means 4, pulls the entire pivoting lever system towards stop 14 into the position shown in broken lines in FIG. 1.

A pressure means arranged to press the endless band 21 of abrading material against the surface of work piece 7 over its entire width at the abrading station is mounted on carrier frame 1. This pressure means includes the following structure:

A pair of pull elements consisting in the illustrated embodiment of a series of pull rods 15, 15' are vertically movably mounted in slots defined in the horizontal bars 12 of the U-shaped carrier means, the pull elements being spaced apart in the direction of the length of the work piece and extending over the width thereof. Pressure roller means consisting in the illustrated embodiment of a series of rollers 16, 16 are mounted at the lower ends of the pull rods and are pressed downwardly against the endless band 21 of abrasive material by elastic element 18 which is mounted between the. carrier frame 1 and a series of bridging members 17 which interconnect the lower ends of the pull rods 15, 15. The downward movement of the pressure rollers 16 ,16' is limited by stops 19, 19' connected to the upper ends of the pull rods and cooperating with horizontal bars 12 to delimit the downward movement of the rods. To exert even pressure over the entire abrasive band, the pressure rollers are pressed against steel band 21 interposed between the rollers and the abrasive band. In the rest position shown in broken lines in FIG. 1, the sensing rollers 9, 9' are below the level of the abrasive band.

When the work piece is moved toward and into the abrading station on endless conveyor 27, its upper surface is in a plane slightly spaced from the plane of abrasive band 21. As the forward edge of the work piece 7 reaches the far edge of the abrasive band (the lefthand edge, as seen in FIG. 1), the work piece is pressed upwardly against and into contact with the abrasive band by operating pressure roller 22 whose axle 23, in a known manner, is reciprocable into pressure contact with conveyor 27, the two rotatable rolls 24, 25 being journaled on a pair of arms extending from the axle of pressure roller 22. In thismanner, work piece 7 is pressed upwardly into operating contact with abrasive band 21, thus forcing sensing rollers 9" from the rest position (shown in broken lines in FIG. 1) into the working position (shown in full lines). Simultaneously, the pressure means is operated to exert downward pressure on the abrasive band 21 in the following manner:

By lifting the sensing rollers 9 into the operating position (full lines), connecting rods cause rollers 9' to move correspondingly, the entire lever arm system pivoting in unison. This, in turn, causes horizontal bars 12 of the U-shaped carrier means to be lowered into the operating position indicated in full lines, the horizontal lever arms 5, pivoting with the remainder of the pivoting lever arm system. The downward movement of the horizontal bars causes a corresponding downward movement of the pull rods, and the elastic element 18, which may be a rubber tube, for instance, filled with yieldable material, such as air, will exert yieldable pressure on pressure rollers 16, 16, which is transmitted by steel band 20 to abrasive band 21. The stops 19, 19" will now no longer be in contact with the horizontal bars 12. The elastic or yielding pressure assures contact with the entire surface of the work piece.

I nthe rest position indicated in broken lines in FIG. 1, spring means 13 will bias the pivoting lever arm system against stop bar 14, thus forcing horizontal bars 12 of the U-shaped carrier means into the. indicated upper position against stops 19, 19', thus causing disengagement between the abrasive band and the work piece surface. As soon as the work piece has been moved to the position where its end has reached the trailing edge of the abrasive band, i.e. the right-hand edge in FIG. 1, the pressure from rolls 22, 24, 25 is released to protect the trailing edge of the work piece against abrasion.

The modification illustrated in FIG. 2 differs from the above-described embodiment only in certain aspects, and to avoid redundancy, like parts operating in a like manner as designated by the same reference numerals.

In this embodiment, too, the pivoting lever arm system is biased against a stop bar on carrier frame 1a by spring 13a, and the U-shaped bar means 11a has a horizontal bar means 12a. However, compression springs 26, 26, are mounted about the. upper ends of the pull rods 15, 15, being held under compression by nuts 26a, 26a. When pivoting of the lever arm system causes horizontal bars means 12a to be depressed and to exert yieldable downward pressure on rollers 16, 16' via elastic element 18, the pressure of springs 26, 26 is released.

I claim:

1. An apparatus for abrading the surface of a Work piece having a width and a length, comprising (a) a conveyor for moving the work piece in the direction of its length of an abrading station;

(b) an endless band of abrasive material mounted for movement in contact with, and in the direction of the width of, said surface at said abrading station;

(0) pressure means arranged to press the endless band of abrasive material against the surface over its entire width at said abrading station; and

(d) a carrier frame for the pressure means extending in the direction of the length of the work piece and having a width exceeding the width of the endless band whereby the two lateral ends of the carrier frame project beyond the width of the endless band, the carrier frame including (1) a pivoting element mounted on each lateral end of the carrier frame for pivoting about an axis extending in the direction of the movement of the endless band,

(2) upright lever arm means affixed to each pivoting element for pivoting in unison therewith,

(3) horizontal lever arm means affixed to each pivoting element for pivoting in unison therewith, and

(4) oblique lever arm means aflixed to each pivoting element for pivoting in unison therewith, the oblique lever arm means enclosing an acute angle with conveyor in the direction of its movement.

2. The apparatus of claim 1, further comprising connecting rod means linking the outer ends of the upright lever means of each of the pivoting elements, said connecting rod means extending in the direction of the length of the work pieces; U-shaped carrier means having a horizontal bar means extending in the direction of the length of the work piece, the U-shaped carrier means linking the outer ends of the horizontal lever means of each of the pivoting elements, the horizontal bar means defining a pair of slots; the pressure means including a pair of pull elements vertically movably extending through the slots, the pull elements being spaced apart in the direc tion of the length of the work piece and extending over the width thereof, pressure roller means at the lower ends of the pull elements and pressing against the endless band of abrasive material; and sensing roller means at the outer ends of the oblique lever arm means.

3. The apparatus of claim 1, further comprises a stop means mounted on the carrier frame, and tension spring means biasing the upright lever arm means against the stop means in the direction of the movement of the work piece.

4. The apparatus of claim 1, further comprising an elastic element mounted between the carrier frame and the pressure means.

5. The apparatus of claim 1, further comprising U- shaped carrier means having a horizontal bar means extending in the direction of the length of the work piece, the U-shaped carrier means linking the outer ends of the horizontal lever means of each of the pivoting elements, the horizontal bar means defining a pair of slots; and the pressure means including a pair of pull elements vertically movably extending through the slots, the pull elements being spaced apart in the direction of the length of the work piece and extending over the Width thereof, compression spring means resiliently mounting the pull elements on the carrier frame, pressure roller means at the lower ends of the pull elements and pressing against the endless band of abrasive material, a bridging means interconnecting the lower ends of the pull elements, and an elastic element mounted between the horizontal bar means of the U-shaped carrier means and the bridging m ns;

6. The apparatus of claim 1, wherein each of said lever arm means consists of a series of like levers adjacently mounted on the pivoting elements along the axes thereof.

7. The apparatus of claim 6, further comprising a series of connecting rods linking respective ones of the outer ends of the upright levers of each of the pivoting elements, said connecting rods extending in the direction of the length of the work piece; a like series of U-shaped carriers each having a horizontal bar extending in the direction of the length of the work piece, the U-shaped carriers linking respective ones of the outer ends of the horizontal levers of each of the pivoting elements, each horizontal bar defining a pair of slots; the pressure means including a series of pairs of pull rods vertically movably extending through the slots, the pull rods of each pair being spaced apart in the direction of the length of the work piece and the series of pull rod pairs extending over the width thereof, pressure rollers at the lower ends of the pull rods and pressing against the endless band of abrasive material, and bridging members interconnecting the lower ends of each pair of pull rods; and sensing rollers at the outer ends of the oblique lever arms.

References Cited UNITED STATES PATENTS OTHELL M. SIMPSON, Primary Examiner US. 01. X.R, 51-14r 

